In high end packet switches buffer management, scheduling, and billing functions will most likely be disconnected from any encapsulation, and framing functions, i.e. these two different sets of functions will most likely be implemented in different sub-components. In this scenario, a simple back-pressure based approach of running Scheduler slightly faster and then back-pressuring it to account for any encapsulation and framer overhead downstream will not give accurate scheduling. Billing information will also not be accurate without accounting for encapsulation and framing overhead downstream.
In the present invention, expressions are given to accurately account for any packet size changes to the downstream of the Scheduling and Billing functions to provide accurate scheduling and billing as per packet size sent on the physical line.
The present invention gives accurate scheduling and billing information as per packet size (bandwidth utilization) on the physical line, instead of basing schedule rates and billing information as per packet size that is stored in the switch internal memory. Also, with programmable parameters downstream packet size changes can be accounted for due to different encapsulation and framing methodologies.